The present invention relates to novel fluorine-containing dicarboxylic acids and novel polymer compounds derived from the same.
Polyester, polyamide, polyimide, and polybenzoxazole have been developed as representatives of organic polymers having high heat resistance. They form a large market in electronic device field, engineering plastic field for automobile and aerospace uses, etc., fuel cell field, medical material field, optical material field, etc. As their center, various many polymers have been put into practical uses, such as polyamides represented by nylon and Kevlar, polyacrylates used for liquid crystal polymers, polyimides represented by Kapton, and polybenzoxazoles represented by Zylon.
It is possible to produce polyester by a process by a polycondensation between dicarboxylic acid and diol in the presence of a condensing agent or by a process by converting dicarboxylic acid into an acid chloride or ester, followed by a polycondensation with diol. It is possible to produce polyamide by a process by a polycondensation between dicarboxylic acid and diamine in the presence of a condensing agent or by a process by converting dicarboxylic acid into a carboxylic chloride or ester, followed by a polycondensation with diamine. It is possible to produce polyimide by polymerizing diamine with tetracarboxylic dianhydride, followed by a dehydration, ring-closing reaction. It is possible to produce polybenzoxazole by a process by a polycondensation between dicarboxylic acid and bisaminophenol in the presence of a condensing agent and then a dehydration, ring-closing reaction. Alternatively, it may be conducted by converting dicarboxylic acid into a carboxylic chloride or ester, then a polycondensation with bisaminophenol, and then a dehydration, ring-closing reaction.
In research and development of these resins, it has widely been tried to introduce a hydroxy group(s), which is not directly involved in the polymerization (polycondensation) and remains in the resin even after the polycondensation, into the monomer to provide the resin with a further function(s). For example, in Japanese Patent Application Publication 2003-268233 A (Patent Publication 1), a phenolic hydroxy group is introduced as a photosensitive group for providing the resin with alkali solubility. In Japanese Patent Application Publication 2003-206352 A (Patent Publication 2), a phenolic hydroxy group is introduced as an adhesive group for providing adhesion between fibers and a resin matrix in a composite material. In International Publication WO 2007/010932 A1 or its corresponding Canadian Patent Application Publication 2614648 A1 (Patent Publication 3), a phenolic hydroxy group is introduced as a crosslinking point moiety.
The resin of Patent Publication 1 is described therein as a polybenzoxazole. To produce this polybenzoxazole, there is conducted a polycondensation between a bisaminophenol derivative (a polymerizable monomer), in which an amino group and a phenolic hydroxy group are adjacent to each other, and a dicarboxylic acid, thereby firstly synthesizing a polyamidephenol precursor containing phenolic hydroxy groups. The phenolic hydroxy group of this precursor serves as a photosensitive group upon patterning by photolithography and then disappears by the subsequent heating as the precursor is modified into an oxazole ring of the final product.
In contrast, In Patent Publications 2 or 3, hydroxyl group is used mainly as an adhesive group or crosslinking point moiety and partly remains in the final product.
Recently, there have been active research and development in the fields of photoresist material and the like by using fluorine-containing compounds, which are superior in transparency in ultraviolet region, particularly in vacuum ultraviolet region. In particular, fluorine-containing hydroxy compounds (fluorocarbinols) are often used. Fluorine is introduced as fluorocarbinol group to achieve adhesion to substrate, high glass transition point, photosensitivity, while allowing transparency at each wavelength for use, due to acidity of fluorocarbinol group, alkali development property, and the like. Of fluorocarbinol group, particularly hexafluoroisopropanol moiety (i.e., 2,2,2-trifluoro-1-hydroxy-1-(trifluoromethyl)ethyl group) attracts much attention due to its dissolution behavior, anti-swelling property, and high contrast, etc. Therefore, a lot of research and development is conducted (see Journal of Photopolymer Science and Technology, Volume 17, No. 14 (2004) pp. 609-619 (Non-patent Publication 1) and International Publication WO 2006/070728 A1 or its corresponding European Patent Application Publication EP 1832618 A1 (Patent Publication 4)).
Fluorine-containing compounds are under development and practical use in the field of various materials, such as polyolefins and condensed polymers, mainly in the field of advanced materials, due to characteristics of fluorine, such as water repellency, oil repellency, low water absorption, heat resistance, weather resistance, corrosion resistance, transparency, photosensitivity, low refractive index, and low-dielectric constant. In the field of condensed polymers, there are proposals for introducing fluorine into diamine monomers, such as a diamine monomer containing a fluorine atom(s) or trifluoromethyl group(s) substituted for a hydrogen(s) of its benzene ring, a diamine monomer containing a hexafluoroisopropenyl group introduced between two aromatic rings, and a fluorine-containing diamine monomer in which a benzene ring has been subjected to hydrogen reduction. Furthermore, a bishydroxyamine monomer containing a hexafluoroisopropenyl group as a center atomic group and aromatic hydroxyamines at its both sides is in practical use. In this case, it is applied as polybenzoxazole or hydroxy-containing polyimide.
There are, however, few developments of heat resistant polymers (e.g., polyester, polyamide, polyimide, and polybenzoxazole) containing a hexafluoroisopropanol moiety as acidic alcohol (see Patent Publication 4, Japanese Patent Application Publication 2007-119503 or its corresponding European Patent Application Publication EP 1783158 A1 (Patent Publication 5), Japanese Patent Application Publication 2007-119504 or its corresponding European Patent Application Publication EP 1810963 A1 (Patent Publication 6), and U.S. Pat. No. 4,045,408 (Patent Publication 7)).